Picture a number of tables arranged in a rectangle or semicircle. There are chessboards on all the tables and people sitting in chairs along the outside at each board. They are all playing chess. But where is their opponent?

He or she is walking along the inner side of the tables, going from board to board, making moves. This is the chess master, and he or she is playing everybody else at the same time.

It's quite a spectacle. Usually the master will win many if not most of the games, and will lose very few, if any. Sometimes the master does this with a blindfold on. The players call out their moves to the master, and he/she calls out the response.

The number of opponents one master can handle in this way depends on the space available and the amount of players he or she can attract. Anywhere from two or three to hundreds of boards have been accommodated. More usual is between ten and fifty.

Numbers

Statistics are sometimes kept on simultaneous exhibitions, particularly if the master plays blind. World records have even been claimed for simultaneous games. But such exhibitions take a lot of time to complete, and some opponents leave before their games have gone very far. Those unfinished games are scored as another number for the master, and are usually claimed as a win as well.

Karl Podzielny played 575 games simultaneously in 1978. In 30½ hours he won 533, drew 27, and lost 15. Vlastimil Hort played 550 opponents, 201 simultaneously, and lost only 10 games in 1977. The late George Koltanowski played 56 consecutive (not simultaneous) blindfold games and won 50, drew 6 in San Francisco in 1960.

Tandem Simuls

Sometimes more than one master may be in the middle of a simultaneous exhibition. In such a case (a “tandem simul”), each one only plays every second or third move. This can provide a nice chance for the amateur opponents, since the masters may have different styles and thus trip each other up.

Another type of tandem simul is when there are multiple simultaneous exhibitions going on at the same time. This is a common occurrence in chess camps, and happens each year on the East Coast with the famous annual “Chessathon,” where scores of masters volunteer to play hundreds of schoolchildren.